CA2402139C - Measurement of substances in liquids - Google Patents
Measurement of substances in liquids Download PDFInfo
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- CA2402139C CA2402139C CA2402139A CA2402139A CA2402139C CA 2402139 C CA2402139 C CA 2402139C CA 2402139 A CA2402139 A CA 2402139A CA 2402139 A CA2402139 A CA 2402139A CA 2402139 C CA2402139 C CA 2402139C
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/483—Physical analysis of biological material
- G01N33/487—Physical analysis of biological material of liquid biological material
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
- C12Q1/001—Enzyme electrodes
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- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
- C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
- C12Q1/001—Enzyme electrodes
- C12Q1/005—Enzyme electrodes involving specific analytes or enzymes
- C12Q1/006—Enzyme electrodes involving specific analytes or enzymes for glucose
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/28—Electrolytic cell components
- G01N27/30—Electrodes, e.g. test electrodes; Half-cells
- G01N27/327—Biochemical electrodes, e.g. electrical or mechanical details for in vitro measurements
- G01N27/3271—Amperometric enzyme electrodes for analytes in body fluids, e.g. glucose in blood
- G01N27/3272—Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/483—Physical analysis of biological material
- G01N33/487—Physical analysis of biological material of liquid biological material
- G01N33/49—Blood
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
- G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
- G01N33/54366—Apparatus specially adapted for solid-phase testing
- G01N33/54373—Apparatus specially adapted for solid-phase testing involving physiochemical end-point determination, e.g. wave-guides, FETS, gratings
- G01N33/5438—Electrodes
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- Investigating Or Analysing Biological Materials (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
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Abstract
In a method of measuring the concentration of a substance such as glucose in a sample liquid such as blood or interstitial fluid, a measuring device is provided having a working sensor part (6b), a second working sensor part (8b) and a reference sensor part (4b). The sample liquid is applied to the measuring device and an electric current proportional to the concentration of the substance in the sample liquid is measured at each sensor part (6b, 8b). The electric currents are compared to establish the difference. If the difference is greater than a predetermined threshold, an error indication is given. A disposable test strip with two working sensors (6b, 8b) is also disclosed.
Description
Measurement of Substances in Liauids This invention relates to apparatus for measuring the concentration of a substance in a liquid and particularly, but not exclusively, to apparatus for measuring the concentration of glucose in blood or interstitial fluid.
Devices for measuring blood glucose levels are invaluable for diabetics, especially devices that may be used by the sufferers themselves since they may then monitor their own glucose levels and take an appropriate dose of insulin. Correspondingly therefore the accuracy of such devices is very important since an inaccurate reading could lead to the wrong level of insulin being administered which could be very harmful.
It is also the case that in all practical blood glucose measuring systems at least part of the device, i.e. that part which comes into contact with the sample blood, is disposable. This means that it is particularly important that the cost particularly of any disposable parts can be minimised as a user will generally need large numbers of them regularly.
Known glucose measuring devices now favour an electrochemical measurement method over old colorimetric methods. The general principle is that an electric current is measured between two sensor parts called the working and reference sensor parts respectively. The working sensor part comprises an electrode onto which is laid a layer of enzyme reagent which comprises an enzyme and an electron mediator compound. When a potential is applied across the sensor parts a current is generated by the transfer of electrons from the substance being measured (the enzyme substrate), via the enzyme and to the surface of the electrode. The current generated is proportional to both the area of the sensor part and
Devices for measuring blood glucose levels are invaluable for diabetics, especially devices that may be used by the sufferers themselves since they may then monitor their own glucose levels and take an appropriate dose of insulin. Correspondingly therefore the accuracy of such devices is very important since an inaccurate reading could lead to the wrong level of insulin being administered which could be very harmful.
It is also the case that in all practical blood glucose measuring systems at least part of the device, i.e. that part which comes into contact with the sample blood, is disposable. This means that it is particularly important that the cost particularly of any disposable parts can be minimised as a user will generally need large numbers of them regularly.
Known glucose measuring devices now favour an electrochemical measurement method over old colorimetric methods. The general principle is that an electric current is measured between two sensor parts called the working and reference sensor parts respectively. The working sensor part comprises an electrode onto which is laid a layer of enzyme reagent which comprises an enzyme and an electron mediator compound. When a potential is applied across the sensor parts a current is generated by the transfer of electrons from the substance being measured (the enzyme substrate), via the enzyme and to the surface of the electrode. The current generated is proportional to both the area of the sensor part and
- 2 -also the concentration of glucose in the test sample.
Since the area of the working sensor part is supposedly known, the electric current should be proportional to the glucose concentration.
It has been recognised in the art that inaccurate results are obtained if the working sensor part is not fully covered with blood since then its effective area is reduced. Various ways of dealing with this problem have been proposed, two of which are disclosed in US
5628890 and US 5582697. Both of these methods rely on a unidirectional flow of blood across the surface of the test strip and both initiate the test measurement by detecting the presence of the sample liquid at an electrode or sensor part located downstream of the working sensor part.
The problem of insufficient sample liquid being present and thus the working sensor part not being completely covered may of course be reduced by reducing the size of the working sensor part. However a small area for the working sensor part tends to give a greater variability in calibrated results.
The present inventors have realised that as well as incomplete coverage of the working sensor part, inaccurate results can also arise from occasional defects in the production of the test strips for such devices and also from accidental damage to the working sensor part e.g by a user. As far as the inventors are aware, the only practical way to deal with this problem so far has been to ensure that the printing process used to produce the test strips is as accurate as possible and to rely on adequate quality control.
It is an object of the present invention at least partially to alleviate the above-mentioned disadvantages and when viewed from a first aspect the invention provides a method of measuring the concentration of a substance in a sample liquid comprising: providing a measuring device having a working sensor part, a second
Since the area of the working sensor part is supposedly known, the electric current should be proportional to the glucose concentration.
It has been recognised in the art that inaccurate results are obtained if the working sensor part is not fully covered with blood since then its effective area is reduced. Various ways of dealing with this problem have been proposed, two of which are disclosed in US
5628890 and US 5582697. Both of these methods rely on a unidirectional flow of blood across the surface of the test strip and both initiate the test measurement by detecting the presence of the sample liquid at an electrode or sensor part located downstream of the working sensor part.
The problem of insufficient sample liquid being present and thus the working sensor part not being completely covered may of course be reduced by reducing the size of the working sensor part. However a small area for the working sensor part tends to give a greater variability in calibrated results.
The present inventors have realised that as well as incomplete coverage of the working sensor part, inaccurate results can also arise from occasional defects in the production of the test strips for such devices and also from accidental damage to the working sensor part e.g by a user. As far as the inventors are aware, the only practical way to deal with this problem so far has been to ensure that the printing process used to produce the test strips is as accurate as possible and to rely on adequate quality control.
It is an object of the present invention at least partially to alleviate the above-mentioned disadvantages and when viewed from a first aspect the invention provides a method of measuring the concentration of a substance in a sample liquid comprising: providing a measuring device having a working sensor part, a second
- 3 -working sensor part and a reference sensor part;
applying the sample liquid to said measuring device;
measuring an electric current at each sensor part proportional to the concentration of said substance in the sample liquid; comparing the electric current from each of the working sensor parts to establish a difference parameter; and giving an indication of an error if said difference parameter is greater than a predetermined threshold.
Thus it will be seen that in accordance with the invention the substance-concentration-dependent current is effectively measured twice and the two measurements compared so that each can be used as a check for the other.
The invention is considered to be particularly beneficial in the context of electrochemical assays in which the substance whose concentration it is desired to check, e.g. glucose in blood, reacts with an element of on the working sensor parts, e.g. an enzyme reagent, to generate charge carriers and thereby give rise to the electric current proportional to the concentration of the substance in the liquid.
Furthermore the measuring device used in this method is novel and inventive in its own right and thus from a second aspect the present invention provides a device for measuring the concentration of a substance in a sample liquid, said device comprising a reference sensor part and a working sensor part for generating charge carriers in proportion to the concentration of said substance in the sample liquid; wherein said device further comprises a second working sensor part also for generating charge carriers in proportion to the concentration of said substance in the sample liquid.
Thus it will be seen that in accordance with the invention the measuring device compares the current passed by two working sensor parts as a result of their generation of charge carriers and gives an error
applying the sample liquid to said measuring device;
measuring an electric current at each sensor part proportional to the concentration of said substance in the sample liquid; comparing the electric current from each of the working sensor parts to establish a difference parameter; and giving an indication of an error if said difference parameter is greater than a predetermined threshold.
Thus it will be seen that in accordance with the invention the substance-concentration-dependent current is effectively measured twice and the two measurements compared so that each can be used as a check for the other.
The invention is considered to be particularly beneficial in the context of electrochemical assays in which the substance whose concentration it is desired to check, e.g. glucose in blood, reacts with an element of on the working sensor parts, e.g. an enzyme reagent, to generate charge carriers and thereby give rise to the electric current proportional to the concentration of the substance in the liquid.
Furthermore the measuring device used in this method is novel and inventive in its own right and thus from a second aspect the present invention provides a device for measuring the concentration of a substance in a sample liquid, said device comprising a reference sensor part and a working sensor part for generating charge carriers in proportion to the concentration of said substance in the sample liquid; wherein said device further comprises a second working sensor part also for generating charge carriers in proportion to the concentration of said substance in the sample liquid.
Thus it will be seen that in accordance with the invention the measuring device compares the current passed by two working sensor parts as a result of their generation of charge carriers and gives an error
- 4 -indication if the two currents are too dissimilar - i.e.
the current at one sensor part differs too greatly from what would be expected from considering the current at the other. Not only can this method detect when one of the sensor parts has not been properly covered with sample liquid, but it can also detect if there is a manufacturing defect in either sensor part or if either has been damaged after manufacture, since even with complete coverage of the working sensor parts, an anomalous current will arise at the affected sensor part in such circumstances.
In accordance with the invention the only type of defect or damage which would not necessarily be recognised is one which affected both of the working sensor parts to the same degree. However, this is logically less likely than a defect affecting a single working sensor part and is thus an improvement over the prior art. In practice such a likelihood is considered to be negligible. In any event the invention is not limited to providing just two working sensor parts and the skilled person could therefore choose to provide three or more working sensor parts to further reduce the probability that they are all affected by an identical defect.
Looking at the invention another way, it provides an arrangement whereby for a given total area of working sensor part and thus a given minimum sample volume, detection of inadequate fill and of defects or damage to the working sensor part can be provided by separating the area of the working sensor part into two.
Some or all of the sensor parts may be provided as part of an integrated device. Preferably however at least the working sensor parts are provided on a removable test member. Thus when viewed from a further aspect the present invention provides a test member for measuring the concentration of a substance in a sample liquid comprising a base member and two working sensor
the current at one sensor part differs too greatly from what would be expected from considering the current at the other. Not only can this method detect when one of the sensor parts has not been properly covered with sample liquid, but it can also detect if there is a manufacturing defect in either sensor part or if either has been damaged after manufacture, since even with complete coverage of the working sensor parts, an anomalous current will arise at the affected sensor part in such circumstances.
In accordance with the invention the only type of defect or damage which would not necessarily be recognised is one which affected both of the working sensor parts to the same degree. However, this is logically less likely than a defect affecting a single working sensor part and is thus an improvement over the prior art. In practice such a likelihood is considered to be negligible. In any event the invention is not limited to providing just two working sensor parts and the skilled person could therefore choose to provide three or more working sensor parts to further reduce the probability that they are all affected by an identical defect.
Looking at the invention another way, it provides an arrangement whereby for a given total area of working sensor part and thus a given minimum sample volume, detection of inadequate fill and of defects or damage to the working sensor part can be provided by separating the area of the working sensor part into two.
Some or all of the sensor parts may be provided as part of an integrated device. Preferably however at least the working sensor parts are provided on a removable test member. Thus when viewed from a further aspect the present invention provides a test member for measuring the concentration of a substance in a sample liquid comprising a base member and two working sensor
- 5 -parts provided on the base member, each working sensor part being arranged in use to generate charge carriers in proportion to the concentration of said substance in the sample liquid.
Preferably a reference sensor part is also provided on the base member.
It will be appreciated by those skilled in the art that effectively what has been provided is a measuring device which is self-testing for proper use, damage and certain manufacturing defects. This is particularly beneficial in the context of a device in which the sensor parts are provided on a separate test member since this may typically be a mass-manufactured test strip, e.g. for measuring blood glucose levels. Such strips would typically be used by a lay person who would not necessarily treat them with sufficient care to prevent damage. Thus in a preferred embodiment the removable test member comprises a disposable test strip.
Since in accordance with the invention a damaged or defective test strip will be recognised, allowing it to be rejected, the accuracy of the final result and thus potentially the safety of a user is no longer solely dependent upon high manufacturing precision and proper careful use. At least in the latter regard, the preferred embodiments of the invention provide an additional layer of safety compared to known arrangements. Although it is of course not desirable that a large number of tests is rejected, in many circumstances it is more important that inaccurate results are not given.
The two working sensor parts may be arranged as convenient within the device, or in accordance with the preferred embodiment, on the test member. The device or test member may be arranged to allow the sample liquid to flow freely over the working sensor parts. More preferably however the sample liquid is constrained to flow substantially unidirectionally across the working WO 01/67099 PCT/GBOi/00990
Preferably a reference sensor part is also provided on the base member.
It will be appreciated by those skilled in the art that effectively what has been provided is a measuring device which is self-testing for proper use, damage and certain manufacturing defects. This is particularly beneficial in the context of a device in which the sensor parts are provided on a separate test member since this may typically be a mass-manufactured test strip, e.g. for measuring blood glucose levels. Such strips would typically be used by a lay person who would not necessarily treat them with sufficient care to prevent damage. Thus in a preferred embodiment the removable test member comprises a disposable test strip.
Since in accordance with the invention a damaged or defective test strip will be recognised, allowing it to be rejected, the accuracy of the final result and thus potentially the safety of a user is no longer solely dependent upon high manufacturing precision and proper careful use. At least in the latter regard, the preferred embodiments of the invention provide an additional layer of safety compared to known arrangements. Although it is of course not desirable that a large number of tests is rejected, in many circumstances it is more important that inaccurate results are not given.
The two working sensor parts may be arranged as convenient within the device, or in accordance with the preferred embodiment, on the test member. The device or test member may be arranged to allow the sample liquid to flow freely over the working sensor parts. More preferably however the sample liquid is constrained to flow substantially unidirectionally across the working WO 01/67099 PCT/GBOi/00990
- 6 -sensor parts.
It is particularly preferred that the two working sensor parts are arranged one downstream of the other.
This makes it possible to ensure that one of the sensor parts will always be completely covered before the other begins to be covered, thus avoiding the possibility, however small, that insufficient sample liquid is applied to cover both sensor parts and furthermore that each sensor part is partially covered by the same amount. It will be appreciated however that if the above-mentioned small risk is deemed acceptable, arrangements in accordance with the invention allow a much greater flexibility in the placement of the sensor parts than in known devices whilst still providing protection against an inadequate volume of sample liquid being used or other incorrect product usage or damage.
Most preferably both working sensor parts are downstream of the reference sensor part.
The currents generated by the two working sensor parts may not be directly comparable, e.g. because the sensor parts are dissimilar, in which case the measuring device is preferably arranged to apply appropriate weights to the measurements returned by one or both working sensor parts to normalise them. The difference parameter could then for example be the simple arithmetic difference between the normalised current values. Preferably however both sensor parts comprise the same working material and alternatively, but preferably additionally, both working sensor parts have the same area. Thus it is most preferred that the two working sensor parts are substantially identical. This enables the difference parameter easily to comprise a direct comparison between the respective currents at the sensor parts in order to determine whether a reliable measurement of the substance concentration can be made.
The threshold used to determine an inaccurate measurement may be chosen as appropriate. Typically a threshold will be chosen empirically as a suitable value will depend on the inherent variability in the manufacturing process, the desired precision of results, etc. To some extent there is a trade-off between the accuracy which may be obtained by setting the threshold low and the proportion of measurements which are disregarded as being too inaccurate. Thus the threshold might advantageously be set at a level for example where no significant harm would be done to a patient relying on the results to administer insulin.
The difference parameter may be an absolute value -e.g. the difference in currents measured at each sensor part, but is preferably dimensionless - e.g. a percentage of one or other of the measured currents.
Preferably the currents are measured after a predetermined time, although this is not necessarily essential.
The actual current value used to calculate the concentration of the substance may just be that from one of the working sensor parts, but is preferably a combination thereof, e.g. the sum or mean of the two.
This gives the advantage that the maximum effective working area is utilised which further helps to increase the precision of the results obtained.
A particularly preferred embodiment of the invention is a device for measuring the concentration of glucose in blood, in which the two working sensor parts and the reference sensor part are provided on a disposable test strip.
A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
Figure 1 shows a base member for a test strip in accordance with the invention;
Figure 2 shows the layout of carbon tracks applied to the base member;
Figure 3 shows the layer of insulation applied to g _ the strip;
Figure 4 shows the enzyme reagent layer;
Figure 5 shows an adhesive layer;
Figure 6 shows a layer of hydrophilic film;
Figure 7 shows the cover layer of the strip;
Figure 8 is a plot of the results obtained without using a method in accordance with the invention; and Figure 9 is a plot similar to Figure 8 obtained using a method in accordance with the invention.
Turning to Figure l, there is shown an oblong polyester strip 2 which forms the base of a test strip for measuring the concentration of glucose in a sample of blood. The base member 2 is shown in isolation although in practice an array of such strips is cut out from a large master sheet at the end of fabrication.
Figure 2 shows the pattern of carbon ink which in this example is applied to the base member by screen printing, although any suitable deposition technique known in the art could be used. The layer of carbon comprises four distinct areas which are electrically insulated from one another. The first track 4 forms, at the distal end thereof, an electrode 4b for a reference/counter sensor part. The track 4 extends lengthwise to form a connecting terminal 4a at its proximal end. The second and third tracks 6, 8 form electrodes 6b, 8b at their distal ends for two working sensor parts and respective connecting terminals 6a, 8a at their proximal ends. The fourth carbon area is simply a connecting bridge 10 which is provided in order to close a circuit in a suitable measuring device in order to turn it on when the test strip has been properly inserted.
Figure 3 shows the next layer to be applied also by screen printing. This is a water insoluble insulating mask 12 which defines a window over the electrodes 4b, 6b, 8b and which therefore controls the size of the exposed carbon and hence where the enzyme reagent layer 14 (Fig. 4) will come into contact with the carbon electrodes. The size and shape of the window are set so that the two electrodes 6b, 8b have a patch of enzyme of exactly the same area printed onto them. This means that for a given potential, each working sensor part will theoretically pass the same electric current in the presence of a sample of blood.
An enzyme layer, in this embodiment a glucose oxidase reagent layer 14 (Fig. 4), is printed over the mask 12 and thus onto the electrodes 4b, 6b, 8b through the window in the mask to form the reference/ counter sensor part and the two working sensor parts respectively. A 150 micron layer of adhesive is then printed onto the strip in the pattern shown in Figure 5.
This pattern has been enlarged for clarity as compared to the previous Figures. Three separate areas of adhesive 16a, 16b, 16c together define a sample chamber 18 between them.
Two sections of hydrophilic film 20 (Fig. 6) are laminated onto the distal end of the strip and are held in place by the adhesive 16. The first section of film has the effect of making the sample chamber 18 into a thin channel which draws liquid into and along it by a capillary action. The final layer is shown in Figure 7 and is a protective plastic cover tape 22 which has a transparent portion 24 at the distal end. This enables a user to tell instantly if a strip has been used and also assists in affording a crude visual check as to whether enough blood has been applied.
Use of the strip will now be described. The test strip is inserted into a meter device. The bridge portion 10 completes a circuit in the device and thus automatically turns the device on. The device also has contacts to connect to the terminals 4a, 6a, 8a on the strip. The measuring device applies a potential of 400 mV between the counter/reference sensor part and each of the two working sensor parts via the above-mentioned terminals.
A drop of blood is then placed on the distal end of the strip. Capillary action draws the blood along the sample chamber 18 and over the counter/reference sensor part and two working sensor parts.
After a predetermined time the electric current passed by each working sensor part is measured and the two measurements are compared. If they differ by more than loo an error message is displayed on the measuring device and the test must be repeated. If they are within l00 of each other however, the two currents are added together in the device and are converted to a glucose level which is displayed on an LCD.
A comparative experiment was carried out using a strip fabricated as set out above, in order to exemplify the benefits achievable in accordance with the invention. In the experiment drops of blood increasing in volume from 1 to 2 micro litres in steps of 0.2 micro litres and with a constant glucose concentration, were applied to such strips, with each volume being repeated 8 times. The current measured at each working sensor part was measured and recorded. The results are shown in Table 1 appended to this description.
For the first part of the test the two currents were simply added together to simulate a single working sensor part having their combined area. These results are plotted in Figure 8.
In the second half of the test the two currents were first compared. Only if they differed by less than loo were they then added together and put forward as valid results. Values differing by more than loo were disregarded. The results of this second part of the test are plotted in Figure 9.
It is immediately apparent that the second set of results is significantly more precise, i.e. they display a much lower variation. Furthermore, since in practice the two working sensor parts will only give results WO 01/67099 PCT/GBOi/00990 consistent with one another if they are both fully covered, the second set of results is also significantly more accurate than the first since it may be safely assumed that the results are only actually given when both working sensor parts are fully covered.
Thus it will be seen that in its preferred embodiment the present invention allows the detection and rejection of those tests that have had insufficient sample applied to the test strip i.e those in which the test strip has been incorrectly used. Similarly it will also allow the detection and rejection of test strips which are defective either through damage or manufacturing defect.
It will be appreciated by those skilled in the art that many variations on what has been described above are possible within the scope of the invention. For example the invention may be used to measure the level of any suitable substance in any liquid, not just glucose in blood. Furthermore, the working sensor parts need not be provided on a test strip but may be part of an integrated device. Also the difference figure of l00 used in the embodiment described above is purely exemplary and any suitable figure may be chosen.
Table 1 Volume Working 1: Working 2: o Error No ~L ~A ~.A Difference checked error check 1 7.07 0.00 -706800 7.07 1 6.94 5.98 -16.2175732 12.92 1 5.53 0.01 -92050 5.54 1 6.99 7.09 1.42393909 14.09 14.09 1 7.34 7.02 -4.59016393 14.35 14.35 1 7.16 6.79 -5.49742078 13.94 13.94 1 7.01 3.47 -102.13441 10.48 1 7.07 5.69 -24.2578605 12.77 1.2 7.18 4.54 -58.2286847 11.72 1.2 7.00 6.78 -3.35055351 13.78 13.78 1.2 7.09 1.79 -297.032475 8.88 1.2 6.31 0.00 -157550 6.31 1.2 6.78 6.79 0.11788977 13.56 13.56 1.2 6.95 6.59 -5.4029443 13.53 13.53 1.2 6.62 6.28 -5.36795158 12.89 12.89 1.2 7.23 3.78 -91.2721502 11.01 1.4 7.16 6.90 -3.76811594 14.06 14.06 1.4 7.14 6.94 -2.88184438 14.08 14.08 1.4 7.17 7.02 -2.13675214 14.19 14.19 1.4 7.02 6.01 -1.5918958 13.93 13.93 1.4 6.95 6.91 -0.5788712 13.86 13.86 1.4 6.93 6.88 -0.72674419 13.81 13.81 1.4 7.09 6.92 -2.4566474 14.01 14.01 1.4 7.25 7.40 2.02702703 14.65 14.65 1.6 7.808 6.59 -18.4825493 14.40 1.6 6.774 6.589 -2.80770982 13.36 13.36 1.6 6.928 6.904 -0.34762457 13.83 13.83 WO 01/67099 PCT/GBOi/00990 1.6 6.892 6.453 -6.80303735 13.35 13.35 1.6 7.087 7.314 3.10363686 14.40 14.40 1.6 7.257 6.947 -4.46235785 14.20 14.20 1.6 6.501 6.306 -3.09229305 12.81 12.81 1.6 6.811 6.755 -0.82901554 13.57 13.57 1.8 7.145 6.536 -9.31762546 13.68 13.68 1.8 7.021 6.612 -6.18572293 13.63 13.63 1.8 6.917 6.828 -1.30345636 13.75 13.75 1.8 6.971 6.78 -2.81710914 13.75 13.75 1.8 7.016 6.941 -1.08053595 13.96 13.96 1.8 6.977 7.179 2.81376236 14.16 14.16 1.8 6.946 6.794 -2.23726828 13.74 13.74 1.8 7.203 7.183 -0.27843519 14.39 14.39 2 7.145 6.536 -9.31762546 13.68 13.68 2 7.021 6.621 -6.18572293 13.63 13.63 2 6.917 6.828 -1.30345636 13.75 13.75 2 6.971 6.78 -2.81710914 13.75 13.75 2 7.016 6.941 -1.08053595 13.96 13.96 2 6.977 7.179 2.81376236 14.16 14.16 2 6.946 6.794 -2.23726818 13.74 13.74 2 7.203 7.183 -0.27843519 14.39 14.39
It is particularly preferred that the two working sensor parts are arranged one downstream of the other.
This makes it possible to ensure that one of the sensor parts will always be completely covered before the other begins to be covered, thus avoiding the possibility, however small, that insufficient sample liquid is applied to cover both sensor parts and furthermore that each sensor part is partially covered by the same amount. It will be appreciated however that if the above-mentioned small risk is deemed acceptable, arrangements in accordance with the invention allow a much greater flexibility in the placement of the sensor parts than in known devices whilst still providing protection against an inadequate volume of sample liquid being used or other incorrect product usage or damage.
Most preferably both working sensor parts are downstream of the reference sensor part.
The currents generated by the two working sensor parts may not be directly comparable, e.g. because the sensor parts are dissimilar, in which case the measuring device is preferably arranged to apply appropriate weights to the measurements returned by one or both working sensor parts to normalise them. The difference parameter could then for example be the simple arithmetic difference between the normalised current values. Preferably however both sensor parts comprise the same working material and alternatively, but preferably additionally, both working sensor parts have the same area. Thus it is most preferred that the two working sensor parts are substantially identical. This enables the difference parameter easily to comprise a direct comparison between the respective currents at the sensor parts in order to determine whether a reliable measurement of the substance concentration can be made.
The threshold used to determine an inaccurate measurement may be chosen as appropriate. Typically a threshold will be chosen empirically as a suitable value will depend on the inherent variability in the manufacturing process, the desired precision of results, etc. To some extent there is a trade-off between the accuracy which may be obtained by setting the threshold low and the proportion of measurements which are disregarded as being too inaccurate. Thus the threshold might advantageously be set at a level for example where no significant harm would be done to a patient relying on the results to administer insulin.
The difference parameter may be an absolute value -e.g. the difference in currents measured at each sensor part, but is preferably dimensionless - e.g. a percentage of one or other of the measured currents.
Preferably the currents are measured after a predetermined time, although this is not necessarily essential.
The actual current value used to calculate the concentration of the substance may just be that from one of the working sensor parts, but is preferably a combination thereof, e.g. the sum or mean of the two.
This gives the advantage that the maximum effective working area is utilised which further helps to increase the precision of the results obtained.
A particularly preferred embodiment of the invention is a device for measuring the concentration of glucose in blood, in which the two working sensor parts and the reference sensor part are provided on a disposable test strip.
A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
Figure 1 shows a base member for a test strip in accordance with the invention;
Figure 2 shows the layout of carbon tracks applied to the base member;
Figure 3 shows the layer of insulation applied to g _ the strip;
Figure 4 shows the enzyme reagent layer;
Figure 5 shows an adhesive layer;
Figure 6 shows a layer of hydrophilic film;
Figure 7 shows the cover layer of the strip;
Figure 8 is a plot of the results obtained without using a method in accordance with the invention; and Figure 9 is a plot similar to Figure 8 obtained using a method in accordance with the invention.
Turning to Figure l, there is shown an oblong polyester strip 2 which forms the base of a test strip for measuring the concentration of glucose in a sample of blood. The base member 2 is shown in isolation although in practice an array of such strips is cut out from a large master sheet at the end of fabrication.
Figure 2 shows the pattern of carbon ink which in this example is applied to the base member by screen printing, although any suitable deposition technique known in the art could be used. The layer of carbon comprises four distinct areas which are electrically insulated from one another. The first track 4 forms, at the distal end thereof, an electrode 4b for a reference/counter sensor part. The track 4 extends lengthwise to form a connecting terminal 4a at its proximal end. The second and third tracks 6, 8 form electrodes 6b, 8b at their distal ends for two working sensor parts and respective connecting terminals 6a, 8a at their proximal ends. The fourth carbon area is simply a connecting bridge 10 which is provided in order to close a circuit in a suitable measuring device in order to turn it on when the test strip has been properly inserted.
Figure 3 shows the next layer to be applied also by screen printing. This is a water insoluble insulating mask 12 which defines a window over the electrodes 4b, 6b, 8b and which therefore controls the size of the exposed carbon and hence where the enzyme reagent layer 14 (Fig. 4) will come into contact with the carbon electrodes. The size and shape of the window are set so that the two electrodes 6b, 8b have a patch of enzyme of exactly the same area printed onto them. This means that for a given potential, each working sensor part will theoretically pass the same electric current in the presence of a sample of blood.
An enzyme layer, in this embodiment a glucose oxidase reagent layer 14 (Fig. 4), is printed over the mask 12 and thus onto the electrodes 4b, 6b, 8b through the window in the mask to form the reference/ counter sensor part and the two working sensor parts respectively. A 150 micron layer of adhesive is then printed onto the strip in the pattern shown in Figure 5.
This pattern has been enlarged for clarity as compared to the previous Figures. Three separate areas of adhesive 16a, 16b, 16c together define a sample chamber 18 between them.
Two sections of hydrophilic film 20 (Fig. 6) are laminated onto the distal end of the strip and are held in place by the adhesive 16. The first section of film has the effect of making the sample chamber 18 into a thin channel which draws liquid into and along it by a capillary action. The final layer is shown in Figure 7 and is a protective plastic cover tape 22 which has a transparent portion 24 at the distal end. This enables a user to tell instantly if a strip has been used and also assists in affording a crude visual check as to whether enough blood has been applied.
Use of the strip will now be described. The test strip is inserted into a meter device. The bridge portion 10 completes a circuit in the device and thus automatically turns the device on. The device also has contacts to connect to the terminals 4a, 6a, 8a on the strip. The measuring device applies a potential of 400 mV between the counter/reference sensor part and each of the two working sensor parts via the above-mentioned terminals.
A drop of blood is then placed on the distal end of the strip. Capillary action draws the blood along the sample chamber 18 and over the counter/reference sensor part and two working sensor parts.
After a predetermined time the electric current passed by each working sensor part is measured and the two measurements are compared. If they differ by more than loo an error message is displayed on the measuring device and the test must be repeated. If they are within l00 of each other however, the two currents are added together in the device and are converted to a glucose level which is displayed on an LCD.
A comparative experiment was carried out using a strip fabricated as set out above, in order to exemplify the benefits achievable in accordance with the invention. In the experiment drops of blood increasing in volume from 1 to 2 micro litres in steps of 0.2 micro litres and with a constant glucose concentration, were applied to such strips, with each volume being repeated 8 times. The current measured at each working sensor part was measured and recorded. The results are shown in Table 1 appended to this description.
For the first part of the test the two currents were simply added together to simulate a single working sensor part having their combined area. These results are plotted in Figure 8.
In the second half of the test the two currents were first compared. Only if they differed by less than loo were they then added together and put forward as valid results. Values differing by more than loo were disregarded. The results of this second part of the test are plotted in Figure 9.
It is immediately apparent that the second set of results is significantly more precise, i.e. they display a much lower variation. Furthermore, since in practice the two working sensor parts will only give results WO 01/67099 PCT/GBOi/00990 consistent with one another if they are both fully covered, the second set of results is also significantly more accurate than the first since it may be safely assumed that the results are only actually given when both working sensor parts are fully covered.
Thus it will be seen that in its preferred embodiment the present invention allows the detection and rejection of those tests that have had insufficient sample applied to the test strip i.e those in which the test strip has been incorrectly used. Similarly it will also allow the detection and rejection of test strips which are defective either through damage or manufacturing defect.
It will be appreciated by those skilled in the art that many variations on what has been described above are possible within the scope of the invention. For example the invention may be used to measure the level of any suitable substance in any liquid, not just glucose in blood. Furthermore, the working sensor parts need not be provided on a test strip but may be part of an integrated device. Also the difference figure of l00 used in the embodiment described above is purely exemplary and any suitable figure may be chosen.
Table 1 Volume Working 1: Working 2: o Error No ~L ~A ~.A Difference checked error check 1 7.07 0.00 -706800 7.07 1 6.94 5.98 -16.2175732 12.92 1 5.53 0.01 -92050 5.54 1 6.99 7.09 1.42393909 14.09 14.09 1 7.34 7.02 -4.59016393 14.35 14.35 1 7.16 6.79 -5.49742078 13.94 13.94 1 7.01 3.47 -102.13441 10.48 1 7.07 5.69 -24.2578605 12.77 1.2 7.18 4.54 -58.2286847 11.72 1.2 7.00 6.78 -3.35055351 13.78 13.78 1.2 7.09 1.79 -297.032475 8.88 1.2 6.31 0.00 -157550 6.31 1.2 6.78 6.79 0.11788977 13.56 13.56 1.2 6.95 6.59 -5.4029443 13.53 13.53 1.2 6.62 6.28 -5.36795158 12.89 12.89 1.2 7.23 3.78 -91.2721502 11.01 1.4 7.16 6.90 -3.76811594 14.06 14.06 1.4 7.14 6.94 -2.88184438 14.08 14.08 1.4 7.17 7.02 -2.13675214 14.19 14.19 1.4 7.02 6.01 -1.5918958 13.93 13.93 1.4 6.95 6.91 -0.5788712 13.86 13.86 1.4 6.93 6.88 -0.72674419 13.81 13.81 1.4 7.09 6.92 -2.4566474 14.01 14.01 1.4 7.25 7.40 2.02702703 14.65 14.65 1.6 7.808 6.59 -18.4825493 14.40 1.6 6.774 6.589 -2.80770982 13.36 13.36 1.6 6.928 6.904 -0.34762457 13.83 13.83 WO 01/67099 PCT/GBOi/00990 1.6 6.892 6.453 -6.80303735 13.35 13.35 1.6 7.087 7.314 3.10363686 14.40 14.40 1.6 7.257 6.947 -4.46235785 14.20 14.20 1.6 6.501 6.306 -3.09229305 12.81 12.81 1.6 6.811 6.755 -0.82901554 13.57 13.57 1.8 7.145 6.536 -9.31762546 13.68 13.68 1.8 7.021 6.612 -6.18572293 13.63 13.63 1.8 6.917 6.828 -1.30345636 13.75 13.75 1.8 6.971 6.78 -2.81710914 13.75 13.75 1.8 7.016 6.941 -1.08053595 13.96 13.96 1.8 6.977 7.179 2.81376236 14.16 14.16 1.8 6.946 6.794 -2.23726828 13.74 13.74 1.8 7.203 7.183 -0.27843519 14.39 14.39 2 7.145 6.536 -9.31762546 13.68 13.68 2 7.021 6.621 -6.18572293 13.63 13.63 2 6.917 6.828 -1.30345636 13.75 13.75 2 6.971 6.78 -2.81710914 13.75 13.75 2 7.016 6.941 -1.08053595 13.96 13.96 2 6.977 7.179 2.81376236 14.16 14.16 2 6.946 6.794 -2.23726818 13.74 13.74 2 7.203 7.183 -0.27843519 14.39 14.39
Claims (17)
1. A device comprising a reference sensor part and a working sensor part for generating charge carriers in proportion to the concentration of a substance in a sample liquid; a second working sensor part also for generating charge carriers in proportion to the concentration of said substance in the sample liquid; means for measuring an electric current at each working sensor part; and means for comparing the electric current from each of the working sensor parts to establish a difference parameter; and giving an indication of an error if said difference parameter is greater than a predetermined threshold.
2. A device as claimed in claim I arranged such that the sample liquid is constrained to flow substantially unidirectionally across said working sensor parts.
3. A device as claimed in claim 2 wherein said working sensor parts are provided downstream of one another.
4. A device as claimed in claim 2 or 3 wherein said working sensor parts are both provided downstream of the reference sensor part.
5. A device as claimed in any one of claims 1 to 4 wherein said sensor parts each have the same area.
6. A device as claimed in claim 5 wherein said working sensor parts are substantially identical.
7. A device as claimed in any one of claims 1 to 6 wherein said working sensor parts are provided on a removable test member.
B. A device as claimed in claim 7 wherein said removable test member comprises a disposable test strip.
9. A device as claimed in any one of claims 1 to 8 arranged to measure said currents after a predetermined time.
10. A method of measuring the concentration of a substance in a sample liquid comprising: providing a measuring device according to claim 1; applying the sample liquid to said measuring device; measuring an electric current at each sensor part proportional to the concentration of said substance in the sample liquid;
comparing the electric current from each of the working sensor parts to establish a difference parameter; and giving an indication of an error if said difference parameter is greater than a predetermined threshold, and where there is no indication of error converting the electric current of a working sensor part or the combined electric currents of the working sensor parts to a concentration of the substance.
comparing the electric current from each of the working sensor parts to establish a difference parameter; and giving an indication of an error if said difference parameter is greater than a predetermined threshold, and where there is no indication of error converting the electric current of a working sensor part or the combined electric currents of the working sensor parts to a concentration of the substance.
11. A method as claimed in claim 10 wherein said working sensor parts are provided on a removable test member.
12. A method as claimed in claim 11 wherein said reference sensor part is provided on said removable test member.
13. A method as claimed in claim 10, 11 or 12 wherein said working sensor parts each generate charge carriers in proportion to the concentration of said substance in the sample liquid.
14. A method as claimed in any one of claims 10 to 13 comprising measuring the current at each sensor part after a predetermined time.
15. A method for confirming the volumetric sufficiency of a sample liquid applied to an electrochemical measuring device on a test strip, comprising the steps of: providing a measuring device for measuring the concentration of a substance in a sample liquid, said device comprising a first working sensor part for generating charge carriers in proportion to the concentration of said substance in the sample liquid, a second working sensor part also for generating charge carriers in proportion to the concentration of said substance in the sample liquid, and a reference sensor part which is a common reference for both the first and second working sensor parts, wherein said first and second working sensor parts and said reference sensor part are provided on a disposable test strip;
applying the sample liquid to said measuring device;
measuring an electric current at each working sensor part proportional to the concentration of said substance in the sample liquid; comparing the electric current from each of the working sensor parts to establish a difference parameter; and when the difference parameter is greater than a predetermined threshold, establishing an error condition to indicate a lack of sufficient sample volume.
applying the sample liquid to said measuring device;
measuring an electric current at each working sensor part proportional to the concentration of said substance in the sample liquid; comparing the electric current from each of the working sensor parts to establish a difference parameter; and when the difference parameter is greater than a predetermined threshold, establishing an error condition to indicate a lack of sufficient sample volume.
16. The method as claimed in claim 15 comprising measuring the current at each working sensor part after a predetermined time following application of the sample.
17. The method as claimed in claim 15 wherein the substance to be measured is glucose, and each of the working sensor parts generates charge carriers in proportion to the concentration of glucose in the sample liquid.
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PCT/GB2001/000990 WO2001067099A1 (en) | 2000-03-08 | 2001-03-07 | Measurement of substances in liquids |
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EP (4) | EP2056107B1 (en) |
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Families Citing this family (224)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9155496B2 (en) | 1997-03-04 | 2015-10-13 | Dexcom, Inc. | Low oxygen in vivo analyte sensor |
US7885697B2 (en) | 2004-07-13 | 2011-02-08 | Dexcom, Inc. | Transcutaneous analyte sensor |
US7899511B2 (en) | 2004-07-13 | 2011-03-01 | Dexcom, Inc. | Low oxygen in vivo analyte sensor |
US6071391A (en) | 1997-09-12 | 2000-06-06 | Nok Corporation | Enzyme electrode structure |
US6391005B1 (en) | 1998-03-30 | 2002-05-21 | Agilent Technologies, Inc. | Apparatus and method for penetration with shaft having a sensor for sensing penetration depth |
US8346337B2 (en) | 1998-04-30 | 2013-01-01 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
US6949816B2 (en) | 2003-04-21 | 2005-09-27 | Motorola, Inc. | Semiconductor component having first surface area for electrically coupling to a semiconductor chip and second surface area for electrically coupling to a substrate, and method of manufacturing same |
US8688188B2 (en) | 1998-04-30 | 2014-04-01 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
US8974386B2 (en) | 1998-04-30 | 2015-03-10 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
US9066695B2 (en) | 1998-04-30 | 2015-06-30 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
US6175752B1 (en) | 1998-04-30 | 2001-01-16 | Therasense, Inc. | Analyte monitoring device and methods of use |
US8480580B2 (en) | 1998-04-30 | 2013-07-09 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
US8465425B2 (en) | 1998-04-30 | 2013-06-18 | Abbott Diabetes Care Inc. | Analyte monitoring device and methods of use |
US6841052B2 (en) | 1999-08-02 | 2005-01-11 | Bayer Corporation | Electrochemical-sensor design |
US20050103624A1 (en) | 1999-10-04 | 2005-05-19 | Bhullar Raghbir S. | Biosensor and method of making |
US7276146B2 (en) | 2001-11-16 | 2007-10-02 | Roche Diagnostics Operations, Inc. | Electrodes, methods, apparatuses comprising micro-electrode arrays |
WO2001036953A1 (en) | 1999-11-15 | 2001-05-25 | Matsushita Electric Industrial Co., Ltd. | Biosensor, method of forming thin-film electrode, and method and apparatus for quantitative determination |
GB0005564D0 (en) * | 2000-03-08 | 2000-05-03 | Inverness Medical Ltd | Measurjement of substances in liquid |
ES2312719T3 (en) * | 2000-03-28 | 2009-03-01 | Diabetes Diagnostics, Inc. | QUICK RESPONSE GLUCOSE SENSOR METER. |
US8641644B2 (en) | 2000-11-21 | 2014-02-04 | Sanofi-Aventis Deutschland Gmbh | Blood testing apparatus having a rotatable cartridge with multiple lancing elements and testing means |
WO2002044705A1 (en) * | 2000-11-30 | 2002-06-06 | Matsushita Electric Industrial Co., Ltd. | Biosensor, measuring instrument for biosensor, and method of quantifying substrate |
US6560471B1 (en) | 2001-01-02 | 2003-05-06 | Therasense, Inc. | Analyte monitoring device and methods of use |
AU2002348683A1 (en) | 2001-06-12 | 2002-12-23 | Pelikan Technologies, Inc. | Method and apparatus for lancet launching device integrated onto a blood-sampling cartridge |
US8337419B2 (en) | 2002-04-19 | 2012-12-25 | Sanofi-Aventis Deutschland Gmbh | Tissue penetration device |
ES2336081T3 (en) | 2001-06-12 | 2010-04-08 | Pelikan Technologies Inc. | SELF-OPTIMIZATION PUNCTURE DEVICE WITH MEANS OF ADAPTATION TO TEMPORARY VARIATIONS IN CUTANEOUS PROPERTIES. |
US9226699B2 (en) | 2002-04-19 | 2016-01-05 | Sanofi-Aventis Deutschland Gmbh | Body fluid sampling module with a continuous compression tissue interface surface |
US9795747B2 (en) | 2010-06-02 | 2017-10-24 | Sanofi-Aventis Deutschland Gmbh | Methods and apparatus for lancet actuation |
US7981056B2 (en) | 2002-04-19 | 2011-07-19 | Pelikan Technologies, Inc. | Methods and apparatus for lancet actuation |
EP1395185B1 (en) | 2001-06-12 | 2010-10-27 | Pelikan Technologies Inc. | Electric lancet actuator |
US9427532B2 (en) | 2001-06-12 | 2016-08-30 | Sanofi-Aventis Deutschland Gmbh | Tissue penetration device |
US7041068B2 (en) | 2001-06-12 | 2006-05-09 | Pelikan Technologies, Inc. | Sampling module device and method |
US20030032874A1 (en) | 2001-07-27 | 2003-02-13 | Dexcom, Inc. | Sensor head for use with implantable devices |
US20030116447A1 (en) | 2001-11-16 | 2003-06-26 | Surridge Nigel A. | Electrodes, methods, apparatuses comprising micro-electrode arrays |
US20030212379A1 (en) * | 2002-02-26 | 2003-11-13 | Bylund Adam David | Systems and methods for remotely controlling medication infusion and analyte monitoring |
CA2419213C (en) * | 2002-03-07 | 2011-06-21 | Bayer Healthcare Llc | Improved electrical sensor |
US20030186446A1 (en) | 2002-04-02 | 2003-10-02 | Jerry Pugh | Test strip containers and methods of using the same |
US7175642B2 (en) | 2002-04-19 | 2007-02-13 | Pelikan Technologies, Inc. | Methods and apparatus for lancet actuation |
US7547287B2 (en) | 2002-04-19 | 2009-06-16 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US7229458B2 (en) | 2002-04-19 | 2007-06-12 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US7909778B2 (en) | 2002-04-19 | 2011-03-22 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US7892185B2 (en) | 2002-04-19 | 2011-02-22 | Pelikan Technologies, Inc. | Method and apparatus for body fluid sampling and analyte sensing |
US7331931B2 (en) | 2002-04-19 | 2008-02-19 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US9248267B2 (en) | 2002-04-19 | 2016-02-02 | Sanofi-Aventis Deustchland Gmbh | Tissue penetration device |
US8267870B2 (en) | 2002-04-19 | 2012-09-18 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for body fluid sampling with hybrid actuation |
US7297122B2 (en) | 2002-04-19 | 2007-11-20 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US8702624B2 (en) | 2006-09-29 | 2014-04-22 | Sanofi-Aventis Deutschland Gmbh | Analyte measurement device with a single shot actuator |
US7892183B2 (en) | 2002-04-19 | 2011-02-22 | Pelikan Technologies, Inc. | Method and apparatus for body fluid sampling and analyte sensing |
US9795334B2 (en) | 2002-04-19 | 2017-10-24 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for penetrating tissue |
US7976476B2 (en) | 2002-04-19 | 2011-07-12 | Pelikan Technologies, Inc. | Device and method for variable speed lancet |
US9314194B2 (en) | 2002-04-19 | 2016-04-19 | Sanofi-Aventis Deutschland Gmbh | Tissue penetration device |
US8784335B2 (en) | 2002-04-19 | 2014-07-22 | Sanofi-Aventis Deutschland Gmbh | Body fluid sampling device with a capacitive sensor |
US7491178B2 (en) | 2002-04-19 | 2009-02-17 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US7226461B2 (en) | 2002-04-19 | 2007-06-05 | Pelikan Technologies, Inc. | Method and apparatus for a multi-use body fluid sampling device with sterility barrier release |
US8579831B2 (en) | 2002-04-19 | 2013-11-12 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for penetrating tissue |
US7901362B2 (en) | 2002-04-19 | 2011-03-08 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US8360992B2 (en) | 2002-04-19 | 2013-01-29 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for penetrating tissue |
US7674232B2 (en) | 2002-04-19 | 2010-03-09 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US7232451B2 (en) | 2002-04-19 | 2007-06-19 | Pelikan Technologies, Inc. | Method and apparatus for penetrating tissue |
US8221334B2 (en) | 2002-04-19 | 2012-07-17 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for penetrating tissue |
US6964871B2 (en) * | 2002-04-25 | 2005-11-15 | Home Diagnostics, Inc. | Systems and methods for blood glucose sensing |
US20080112852A1 (en) * | 2002-04-25 | 2008-05-15 | Neel Gary T | Test Strips and System for Measuring Analyte Levels in a Fluid Sample |
US6743635B2 (en) | 2002-04-25 | 2004-06-01 | Home Diagnostics, Inc. | System and methods for blood glucose sensing |
US6946299B2 (en) | 2002-04-25 | 2005-09-20 | Home Diagnostics, Inc. | Systems and methods for blood glucose sensing |
US7303726B2 (en) | 2002-05-09 | 2007-12-04 | Lifescan, Inc. | Minimal procedure analyte test system |
KR100485671B1 (en) | 2002-09-30 | 2005-04-27 | 주식회사 인포피아 | A measuring instrument for biosensor |
US9017544B2 (en) | 2002-10-04 | 2015-04-28 | Roche Diagnostics Operations, Inc. | Determining blood glucose in a small volume sample receiving cavity and in a short time period |
JP3878993B2 (en) * | 2002-10-31 | 2007-02-07 | アークレイ株式会社 | Analysis tool |
US8574895B2 (en) | 2002-12-30 | 2013-11-05 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus using optical techniques to measure analyte levels |
US20040193202A1 (en) | 2003-03-28 | 2004-09-30 | Allen John J. | Integrated lance and strip for analyte measurement |
EP1628567B1 (en) | 2003-05-30 | 2010-08-04 | Pelikan Technologies Inc. | Method and apparatus for fluid injection |
US7462265B2 (en) * | 2003-06-06 | 2008-12-09 | Lifescan, Inc. | Reduced volume electrochemical sensor |
US7850621B2 (en) | 2003-06-06 | 2010-12-14 | Pelikan Technologies, Inc. | Method and apparatus for body fluid sampling and analyte sensing |
US20040251132A1 (en) * | 2003-06-06 | 2004-12-16 | Leach Christopher Philip | Reduced volume strip |
WO2006001797A1 (en) | 2004-06-14 | 2006-01-05 | Pelikan Technologies, Inc. | Low pain penetrating |
US7645373B2 (en) | 2003-06-20 | 2010-01-12 | Roche Diagnostic Operations, Inc. | System and method for coding information on a biosensor test strip |
US7452457B2 (en) | 2003-06-20 | 2008-11-18 | Roche Diagnostics Operations, Inc. | System and method for analyte measurement using dose sufficiency electrodes |
JP4619359B2 (en) | 2003-06-20 | 2011-01-26 | エフ ホフマン−ラ ロッシュ アクチェン ゲゼルシャフト | Specimen with sample receiving chamber formed in flare shape |
US8071030B2 (en) | 2003-06-20 | 2011-12-06 | Roche Diagnostics Operations, Inc. | Test strip with flared sample receiving chamber |
US8148164B2 (en) | 2003-06-20 | 2012-04-03 | Roche Diagnostics Operations, Inc. | System and method for determining the concentration of an analyte in a sample fluid |
US7718439B2 (en) | 2003-06-20 | 2010-05-18 | Roche Diagnostics Operations, Inc. | System and method for coding information on a biosensor test strip |
US7645421B2 (en) | 2003-06-20 | 2010-01-12 | Roche Diagnostics Operations, Inc. | System and method for coding information on a biosensor test strip |
US8058077B2 (en) | 2003-06-20 | 2011-11-15 | Roche Diagnostics Operations, Inc. | Method for coding information on a biosensor test strip |
US8206565B2 (en) | 2003-06-20 | 2012-06-26 | Roche Diagnostics Operation, Inc. | System and method for coding information on a biosensor test strip |
GB0314944D0 (en) * | 2003-06-26 | 2003-07-30 | Univ Cranfield | Electrochemical detector for metabolites in physiological fluids |
US8060173B2 (en) | 2003-08-01 | 2011-11-15 | Dexcom, Inc. | System and methods for processing analyte sensor data |
US20080119703A1 (en) | 2006-10-04 | 2008-05-22 | Mark Brister | Analyte sensor |
US20190357827A1 (en) | 2003-08-01 | 2019-11-28 | Dexcom, Inc. | Analyte sensor |
US8788006B2 (en) | 2003-08-01 | 2014-07-22 | Dexcom, Inc. | System and methods for processing analyte sensor data |
US7920906B2 (en) | 2005-03-10 | 2011-04-05 | Dexcom, Inc. | System and methods for processing analyte sensor data for sensor calibration |
WO2005033659A2 (en) | 2003-09-29 | 2005-04-14 | Pelikan Technologies, Inc. | Method and apparatus for an improved sample capture device |
US9351680B2 (en) | 2003-10-14 | 2016-05-31 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for a variable user interface |
US7655119B2 (en) | 2003-10-31 | 2010-02-02 | Lifescan Scotland Limited | Meter for use in an improved method of reducing interferences in an electrochemical sensor using two different applied potentials |
PT1678489E (en) | 2003-10-31 | 2007-06-19 | Lifescan Scotland Ltd | Method of reducing the effect of direct interference current in an electrochemical test strip |
CA2511746C (en) * | 2003-11-06 | 2013-03-26 | Lifescan, Inc. | Drug delivery pen with event notification means |
US9247900B2 (en) | 2004-07-13 | 2016-02-02 | Dexcom, Inc. | Analyte sensor |
US8364231B2 (en) | 2006-10-04 | 2013-01-29 | Dexcom, Inc. | Analyte sensor |
US8423114B2 (en) | 2006-10-04 | 2013-04-16 | Dexcom, Inc. | Dual electrode system for a continuous analyte sensor |
US11633133B2 (en) | 2003-12-05 | 2023-04-25 | Dexcom, Inc. | Dual electrode system for a continuous analyte sensor |
EP1711790B1 (en) | 2003-12-05 | 2010-09-08 | DexCom, Inc. | Calibration techniques for a continuous analyte sensor |
US8287453B2 (en) | 2003-12-05 | 2012-10-16 | Dexcom, Inc. | Analyte sensor |
EP1706026B1 (en) | 2003-12-31 | 2017-03-01 | Sanofi-Aventis Deutschland GmbH | Method and apparatus for improving fluidic flow and sample capture |
US7822454B1 (en) | 2005-01-03 | 2010-10-26 | Pelikan Technologies, Inc. | Fluid sampling device with improved analyte detecting member configuration |
WO2005078118A1 (en) | 2004-02-06 | 2005-08-25 | Bayer Healthcare Llc | Oxidizable species as an internal reference for biosensors and method of use |
DE102004024432A1 (en) * | 2004-05-14 | 2005-12-08 | Tesa Ag | Use of a hydrophilic surface film in medical diagnostic strips |
EP1751546A2 (en) | 2004-05-20 | 2007-02-14 | Albatros Technologies GmbH & Co. KG | Printable hydrogel for biosensors |
US9775553B2 (en) | 2004-06-03 | 2017-10-03 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for a fluid sampling device |
WO2005120365A1 (en) | 2004-06-03 | 2005-12-22 | Pelikan Technologies, Inc. | Method and apparatus for a fluid sampling device |
US7569126B2 (en) | 2004-06-18 | 2009-08-04 | Roche Diagnostics Operations, Inc. | System and method for quality assurance of a biosensor test strip |
DE112005001154B4 (en) | 2004-06-23 | 2011-09-29 | Tesa Se | Medical biosensor used to examine biological fluids |
US20050284773A1 (en) | 2004-06-29 | 2005-12-29 | Allen John J | Method of preventing reuse in an analyte measuring system |
US20070045902A1 (en) | 2004-07-13 | 2007-03-01 | Brauker James H | Analyte sensor |
US7905833B2 (en) | 2004-07-13 | 2011-03-15 | Dexcom, Inc. | Transcutaneous analyte sensor |
US7783333B2 (en) | 2004-07-13 | 2010-08-24 | Dexcom, Inc. | Transcutaneous medical device with variable stiffness |
US7640048B2 (en) | 2004-07-13 | 2009-12-29 | Dexcom, Inc. | Analyte sensor |
US8565848B2 (en) | 2004-07-13 | 2013-10-22 | Dexcom, Inc. | Transcutaneous analyte sensor |
US8652831B2 (en) | 2004-12-30 | 2014-02-18 | Sanofi-Aventis Deutschland Gmbh | Method and apparatus for analyte measurement test time |
US8133178B2 (en) | 2006-02-22 | 2012-03-13 | Dexcom, Inc. | Analyte sensor |
US7713392B2 (en) * | 2005-04-15 | 2010-05-11 | Agamatrix, Inc. | Test strip coding and quality measurement |
US20060246214A1 (en) * | 2005-04-28 | 2006-11-02 | Plotkin Elliot V | Method for manufacturing an electrochemical-based analytical test strip with hydrophilicity enhanced metal electrodes |
US20060243591A1 (en) * | 2005-04-28 | 2006-11-02 | Plotkin Elliot V | Electrochemical-based analytical test strip with hydrophilicity enhanced metal electrodes |
US20070017824A1 (en) * | 2005-07-19 | 2007-01-25 | Rippeth John J | Biosensor and method of manufacture |
MX2008000836A (en) | 2005-07-20 | 2008-03-26 | Bayer Healthcare Llc | Gated amperometry. |
EP1934591B1 (en) | 2005-09-30 | 2019-01-02 | Ascensia Diabetes Care Holdings AG | Gated voltammetry |
US7429865B2 (en) | 2005-10-05 | 2008-09-30 | Roche Diagnostics Operations, Inc. | Method and system for error checking an electrochemical sensor |
US7468125B2 (en) | 2005-10-17 | 2008-12-23 | Lifescan, Inc. | System and method of processing a current sample for calculating a glucose concentration |
US8066866B2 (en) * | 2005-10-17 | 2011-11-29 | Lifescan, Inc. | Methods for measuring physiological fluids |
US9757061B2 (en) | 2006-01-17 | 2017-09-12 | Dexcom, Inc. | Low oxygen in vivo analyte sensor |
EP3756537B1 (en) | 2006-02-22 | 2023-08-02 | DexCom, Inc. | Analyte sensor |
EP1991110B1 (en) | 2006-03-09 | 2018-11-07 | DexCom, Inc. | Systems and methods for processing analyte sensor data |
EP4218548A1 (en) | 2006-03-09 | 2023-08-02 | Dexcom, Inc. | Systems and methods for processing analyte sensor data |
GB2436616A (en) * | 2006-03-29 | 2007-10-03 | Inverness Medical Switzerland | Assay device and method |
US7738264B2 (en) | 2006-03-31 | 2010-06-15 | Lifescan Scotland Ltd. | Devices and methods for protecting handheld electronic devices from electrostatic discharge |
US20100021940A1 (en) * | 2006-04-12 | 2010-01-28 | Astrazeneca Ab | Method for Determining the Activity of a Protease in a Sample |
JP5121822B2 (en) * | 2006-05-08 | 2013-01-16 | バイエル・ヘルスケア・エルエルシー | Abnormal output detection system for biosensor |
US7589828B2 (en) * | 2006-05-26 | 2009-09-15 | Lifescan Scotland Limited | System for analyte determination that includes a permutative grey scale calibration pattern |
US7593097B2 (en) * | 2006-05-26 | 2009-09-22 | Lifescan Scotland Limited | Method for determining a test strip calibration code for use in a meter |
US7474391B2 (en) * | 2006-05-26 | 2009-01-06 | Lifescan Scotland Limited | Method for determining a test strip calibration code using a calibration strip |
US7586590B2 (en) * | 2006-05-26 | 2009-09-08 | Lifescan, Scotland, Ltd. | Calibration code strip with permutative grey scale calibration pattern |
US7474390B2 (en) * | 2006-05-26 | 2009-01-06 | Lifescan Scotland Limited | Test strip with permutative grey scale calibration pattern |
US7831287B2 (en) | 2006-10-04 | 2010-11-09 | Dexcom, Inc. | Dual electrode system for a continuous analyte sensor |
US9046480B2 (en) | 2006-10-05 | 2015-06-02 | Lifescan Scotland Limited | Method for determining hematocrit corrected analyte concentrations |
EP2957908A1 (en) | 2006-10-05 | 2015-12-23 | Lifescan Scotland Limited | Methods for determining an analyte concentration using signal processing algorithms |
EP2074415A1 (en) | 2006-10-05 | 2009-07-01 | Lifescan Scotland Limited | A test strip comprising patterned electrodes |
ES2397663T3 (en) | 2006-10-05 | 2013-03-08 | Lifescan Scotland Limited | Systems and procedures for determining a concentration of an analyte substantially independent of hematocrit |
US8388821B2 (en) | 2006-10-05 | 2013-03-05 | Lifescan Scotland Limited | Method for determining hematocrit corrected analyte concentrations |
EP3753481B1 (en) | 2006-10-24 | 2024-07-17 | Ascensia Diabetes Care Holdings AG | Transient decay amperometry device |
US20080124693A1 (en) * | 2006-10-26 | 2008-05-29 | Mcevoy Mary | System for determining an analyte in a bodily fluid sample that includes a graphics-based step-by-step tutorial module |
US20080164142A1 (en) | 2006-10-27 | 2008-07-10 | Manuel Alvarez-Icaza | Surface treatment of carbon composite material to improve electrochemical properties |
TW200823456A (en) * | 2006-11-24 | 2008-06-01 | Health & Life Co Ltd | Biosensor |
DE102007003755A1 (en) | 2007-01-19 | 2008-07-31 | Tesa Ag | Web-shaped material with a coating that enables a permanent fast spreading or a permanent, very fast transport of liquids |
CA2681412A1 (en) | 2007-03-26 | 2008-10-02 | Dexcom, Inc. | Analyte sensor |
DE102007018383A1 (en) | 2007-04-17 | 2008-10-23 | Tesa Ag | Sheet-like material with hydrophilic and hydrophobic areas and their production |
DE102007026998A1 (en) | 2007-06-07 | 2008-12-11 | Tesa Ag | Hydrophilic coating varnish |
US7875461B2 (en) | 2007-07-24 | 2011-01-25 | Lifescan Scotland Limited | Test strip and connector |
US8762624B2 (en) * | 2007-08-29 | 2014-06-24 | Lifescan Scotland Limited | Data management system and method using nonvolatile and volatile memories and linked lists to sequentially store data records of different category types |
US7943022B2 (en) | 2007-09-04 | 2011-05-17 | Lifescan, Inc. | Analyte test strip with improved reagent deposition |
EP2108125A1 (en) * | 2007-09-05 | 2009-10-14 | Lifescan Scotland Limited | Strip for an electrochemical meter |
EP2040079B1 (en) | 2007-09-19 | 2009-05-20 | F. Hoffman-la Roche AG | Marking method for marking rejects of test elements |
EP2040072B1 (en) * | 2007-09-22 | 2013-01-02 | Roche Diagnostics GmbH | Analysis system for measuring the concentration of an analyte in a bodily fluid |
WO2009076302A1 (en) | 2007-12-10 | 2009-06-18 | Bayer Healthcare Llc | Control markers for auto-detection of control solution and methods of use |
USD612279S1 (en) | 2008-01-18 | 2010-03-23 | Lifescan Scotland Limited | User interface in an analyte meter |
DE102008006225A1 (en) | 2008-01-25 | 2009-07-30 | Tesa Ag | Biosensor and its production |
USD612275S1 (en) | 2008-03-21 | 2010-03-23 | Lifescan Scotland, Ltd. | Analyte test meter |
USD615431S1 (en) | 2008-03-21 | 2010-05-11 | Lifescan Scotland Limited | Analyte test meter |
IL197532A0 (en) | 2008-03-21 | 2009-12-24 | Lifescan Scotland Ltd | Analyte testing method and system |
USD611853S1 (en) | 2008-03-21 | 2010-03-16 | Lifescan Scotland Limited | Analyte test meter |
WO2009126900A1 (en) | 2008-04-11 | 2009-10-15 | Pelikan Technologies, Inc. | Method and apparatus for analyte detecting device |
USD611151S1 (en) | 2008-06-10 | 2010-03-02 | Lifescan Scotland, Ltd. | Test meter |
USD611489S1 (en) | 2008-07-25 | 2010-03-09 | Lifescan, Inc. | User interface display for a glucose meter |
USD611372S1 (en) | 2008-09-19 | 2010-03-09 | Lifescan Scotland Limited | Analyte test meter |
US8994395B2 (en) * | 2008-10-27 | 2015-03-31 | Lifescan Scotland Limited | Methods and devices for mitigating ESD events |
US8012428B2 (en) | 2008-10-30 | 2011-09-06 | Lifescan Scotland, Ltd. | Analytical test strip with minimal fill-error sample viewing window |
US20100112612A1 (en) * | 2008-10-30 | 2010-05-06 | John William Dilleen | Method for determining an analyte using an analytical test strip with a minimal fill-error viewing window |
US9375169B2 (en) | 2009-01-30 | 2016-06-28 | Sanofi-Aventis Deutschland Gmbh | Cam drive for managing disposable penetrating member actions with a single motor and motor and control system |
EP2228658A1 (en) | 2009-03-13 | 2010-09-15 | Roche Diagnostics GmbH | Method for producing an analytical consumable |
US20100270152A1 (en) * | 2009-04-24 | 2010-10-28 | Lifescan Scotland Limited | Enzymatic reagent ink |
US20100273249A1 (en) | 2009-04-24 | 2010-10-28 | Lifescan Scotland Limited | Analytical test strips |
US8025788B2 (en) | 2009-04-24 | 2011-09-27 | Lifescan Scotland Limited | Method for manufacturing an enzymatic reagent ink |
US20110057671A1 (en) | 2009-09-04 | 2011-03-10 | Lifescan Scotland, Ltd. | Methods, system and device to identify a type of test strip |
IL209760A (en) | 2009-12-11 | 2015-05-31 | Lifescan Scotland Ltd | Fill sufficiency method and system |
TWI440853B (en) * | 2009-12-14 | 2014-06-11 | Taidoc Technology Corp | Electrochemical biosensing test strip, biosensing meter, system and measuring method for analyte measurement incorporating a hematocrit correction |
EP2365329A1 (en) * | 2010-03-12 | 2011-09-14 | Hivox Biotek Inc. | Method of manufacturing planar bio-test strip and product thereof |
US8965476B2 (en) | 2010-04-16 | 2015-02-24 | Sanofi-Aventis Deutschland Gmbh | Tissue penetration device |
US8940141B2 (en) | 2010-05-19 | 2015-01-27 | Lifescan Scotland Limited | Analytical test strip with an electrode having electrochemically active and inert areas of a predetermined size and distribution |
US20110290668A1 (en) | 2010-05-27 | 2011-12-01 | Lifescan Scotland Limited | Analytical test strip with crossroads exposed electrode configuration |
US8239582B2 (en) | 2010-05-27 | 2012-08-07 | Cilag Gmbh International | Hand-held test meter with disruption avoidance circuitry |
US20110315564A1 (en) | 2010-06-28 | 2011-12-29 | Cilag Gmbh International | Hand-held test meter with deep power conservation mode |
US9618517B2 (en) * | 2010-09-28 | 2017-04-11 | Lifescan Scotland Limited | Analyte measurement method and system with error trapping |
US20120199498A1 (en) | 2011-02-07 | 2012-08-09 | Manuel Alvarez-Icaza | Electrochemical-based analytical test strip with graded enzymatic reagent layer and related methods |
WO2012142502A2 (en) | 2011-04-15 | 2012-10-18 | Dexcom Inc. | Advanced analyte sensor calibration and error detection |
WO2012164271A1 (en) * | 2011-05-27 | 2012-12-06 | Lifescan Scotland Limited | Peak offset correction for analyte test strip |
US20130006536A1 (en) | 2011-06-28 | 2013-01-03 | Lifescan, Inc. | Hand-held test meter with unpowered usb connection detection circuit |
US20130002266A1 (en) | 2011-06-28 | 2013-01-03 | Lifescan, Inc. | Hand-held test meter with electromagnetic interference detection circuit |
US10739337B2 (en) * | 2011-08-30 | 2020-08-11 | Board Of Trustees Of Michigan State University | Extraction and detection of pathogens using carbohydrate-functionalized biosensors |
US8603309B2 (en) | 2011-09-12 | 2013-12-10 | Nova Biomedical Corporation | Disposable sensor for electrochemical detection of hemoglobin |
US20130084590A1 (en) | 2011-09-30 | 2013-04-04 | Lifescan Scotland Ltd. | Analytical test strip with bodily fluid phase-shift measurement electrodes |
US20130084591A1 (en) | 2011-09-30 | 2013-04-04 | Lifescan Scotland Ltd. | Analytical test strip with isolated bodily fluid phase-shift and analyte determination sample chambers |
US9970933B2 (en) * | 2011-10-06 | 2018-05-15 | Ingibio, Ltd. | Method for manufacturing multiple-diagnosis membrane sensor by using screen printing |
KR101367262B1 (en) * | 2011-11-11 | 2014-02-26 | 주식회사 아이센스 | Blood Glucose Sensor and sensing error detecting method using thereof |
US9572922B2 (en) | 2012-12-21 | 2017-02-21 | Larry Leonard | Inventive diabetic systems, tools, kits, and supplies for better diabetic living and mobility |
US9903830B2 (en) | 2011-12-29 | 2018-02-27 | Lifescan Scotland Limited | Accurate analyte measurements for electrochemical test strip based on sensed physical characteristic(s) of the sample containing the analyte |
US20130199942A1 (en) | 2012-02-07 | 2013-08-08 | Lifescan Scotland Limited | Electrochemical-based analytical test strip with fill-speed configured reagent layer |
US11798685B2 (en) | 2012-05-15 | 2023-10-24 | James M. Minor | Diagnostic methods and devices for controlling acute glycemia |
US9465910B2 (en) | 2012-05-15 | 2016-10-11 | James Minor | Diagnostic methods and devices for monitoring chronic glycemia |
US20130341207A1 (en) | 2012-06-21 | 2013-12-26 | Lifescan Scotland Limited | Analytical test strip with capillary sample-receiving chambers separated by stop junctions |
US9128038B2 (en) | 2012-06-21 | 2015-09-08 | Lifescan Scotland Limited | Analytical test strip with capillary sample-receiving chambers separated by a physical barrier island |
US8877023B2 (en) | 2012-06-21 | 2014-11-04 | Lifescan Scotland Limited | Electrochemical-based analytical test strip with intersecting sample-receiving chambers |
GB201218555D0 (en) * | 2012-10-16 | 2012-11-28 | Mode Diagnostics Ltd | Immunoassay using electrochemical detection |
US9211087B2 (en) | 2012-10-18 | 2015-12-15 | Animas Corporation | Self-contained hand-held test device for single-use |
US9157883B2 (en) | 2013-03-07 | 2015-10-13 | Lifescan Scotland Limited | Methods and systems to determine fill direction and fill error in analyte measurements |
US9097659B2 (en) * | 2013-03-14 | 2015-08-04 | Bayer Healthcare Llc | Maintaining electrode function during manufacture with a protective layer |
US10371660B2 (en) | 2013-05-17 | 2019-08-06 | Lifescan Ip Holdings, Llc | Accurate analyte measurements for electrochemical test strip based on multiple calibration parameters |
GB2514846B (en) | 2013-06-07 | 2015-09-30 | Lifescan Scotland Ltd | Electrochemical-based analytical test strip with a soluble electrochemically-active coating opposite a bare electrode |
US9243276B2 (en) * | 2013-08-29 | 2016-01-26 | Lifescan Scotland Limited | Method and system to determine hematocrit-insensitive glucose values in a fluid sample |
US9459231B2 (en) | 2013-08-29 | 2016-10-04 | Lifescan Scotland Limited | Method and system to determine erroneous measurement signals during a test measurement sequence |
US9828621B2 (en) * | 2013-09-10 | 2017-11-28 | Lifescan Scotland Limited | Anomalous signal error trap for an analyte measurement determined from a specified sampling time derived from a sensed physical characteristic of the sample containing the analyte |
US9453812B2 (en) | 2014-06-24 | 2016-09-27 | Lifescan Scotland Limited | End-fill electrochemical-based analytical test strip with perpendicular intersecting sample-receiving chambers |
CN105445341B (en) * | 2014-09-12 | 2018-10-16 | 达尔生技股份有限公司 | The detection method of the test strip exception of electrochemistry |
US20160091451A1 (en) | 2014-09-25 | 2016-03-31 | Lifescan Scotland Limited | Accurate analyte measurements for electrochemical test strip to determine analyte measurement time based on measured temperature, physical characteristic and estimated analyte value |
US20160091450A1 (en) | 2014-09-25 | 2016-03-31 | Lifescan Scotland Limited | Accurate analyte measurements for electrochemical test strip to determine analyte measurement time based on measured temperature, physical characteristic and estimated analyte value and their temperature compensated values |
CN106990232B (en) * | 2016-01-01 | 2019-05-28 | 海南欣泰康医药科技有限公司 | Blood Kit analysis system and analysis method |
CN110770574B (en) | 2017-06-08 | 2022-07-15 | 豪夫迈·罗氏有限公司 | Electrode breakage detection |
US20190094170A1 (en) | 2017-09-22 | 2019-03-28 | Cilag Gmbh International | Analytical test strip with integrated electrical resistor |
CN108132284B (en) * | 2017-12-26 | 2019-11-29 | 三诺生物传感股份有限公司 | A kind of test method of electrochemical sensor |
Family Cites Families (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5682884A (en) | 1983-05-05 | 1997-11-04 | Medisense, Inc. | Strip electrode with screen printing |
DE68924026T3 (en) * | 1988-03-31 | 2008-01-10 | Matsushita Electric Industrial Co., Ltd., Kadoma | BIOSENSOR AND ITS MANUFACTURE. |
JP2577981B2 (en) * | 1988-12-14 | 1997-02-05 | 株式会社堀場製作所 | Process ion measuring equipment |
US5234813A (en) | 1989-05-17 | 1993-08-10 | Actimed Laboratories, Inc. | Method and device for metering of fluid samples and detection of analytes therein |
JP2960265B2 (en) * | 1991-10-18 | 1999-10-06 | 松下電器産業株式会社 | Biosensor and measurement method using the same |
US5264103A (en) | 1991-10-18 | 1993-11-23 | Matsushita Electric Industrial Co., Ltd. | Biosensor and a method for measuring a concentration of a substrate in a sample |
JP3189416B2 (en) * | 1992-09-25 | 2001-07-16 | 松下電器産業株式会社 | Liquid component measuring device |
US5837546A (en) | 1993-08-24 | 1998-11-17 | Metrika, Inc. | Electronic assay device and method |
US5791344A (en) * | 1993-11-19 | 1998-08-11 | Alfred E. Mann Foundation For Scientific Research | Patient monitoring system |
US5762770A (en) | 1994-02-21 | 1998-06-09 | Boehringer Mannheim Corporation | Electrochemical biosensor test strip |
KR0151203B1 (en) * | 1994-12-08 | 1998-12-01 | 이헌조 | Multi-electrode type biosensor |
US5650062A (en) | 1995-03-17 | 1997-07-22 | Matsushita Electric Industrial Co., Ltd. | Biosensor, and a method and a device for quantifying a substrate in a sample liquid using the same |
JP3102627B2 (en) * | 1995-03-17 | 2000-10-23 | 松下電器産業株式会社 | Biosensor, quantitative method and quantitative device using the same |
US5582697A (en) | 1995-03-17 | 1996-12-10 | Matsushita Electric Industrial Co., Ltd. | Biosensor, and a method and a device for quantifying a substrate in a sample liquid using the same |
US5786584A (en) | 1995-09-06 | 1998-07-28 | Eli Lilly And Company | Vial and cartridge reading device providing audio feedback for a blood glucose monitoring system |
US5628890A (en) | 1995-09-27 | 1997-05-13 | Medisense, Inc. | Electrochemical sensor |
JP3365184B2 (en) * | 1996-01-10 | 2003-01-08 | 松下電器産業株式会社 | Biosensor |
US5708247A (en) | 1996-02-14 | 1998-01-13 | Selfcare, Inc. | Disposable glucose test strips, and methods and compositions for making same |
TW591230B (en) * | 1997-10-14 | 2004-06-11 | Bayer Ag | Method for improving the accuracy of the semi-quantitative determination of analyte in fluid samples |
JP3267933B2 (en) * | 1998-01-27 | 2002-03-25 | 松下電器産業株式会社 | Substrate quantification method |
US6587705B1 (en) | 1998-03-13 | 2003-07-01 | Lynn Kim | Biosensor, iontophoretic sampling system, and methods of use thereof |
GB2337122B (en) | 1998-05-08 | 2002-11-13 | Medisense Inc | Test strip |
US6258229B1 (en) * | 1999-06-02 | 2001-07-10 | Handani Winarta | Disposable sub-microliter volume sensor and method of making |
US6287451B1 (en) * | 1999-06-02 | 2001-09-11 | Handani Winarta | Disposable sensor and method of making |
GB0005564D0 (en) * | 2000-03-08 | 2000-05-03 | Inverness Medical Ltd | Measurjement of substances in liquid |
-
2000
- 2000-03-08 GB GBGB0005564.0A patent/GB0005564D0/en not_active Ceased
- 2000-03-08 US US09/521,163 patent/US6733655B1/en not_active Expired - Lifetime
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2001
- 2001-03-07 RU RU2002126614/14A patent/RU2269779C2/en active
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- 2001-03-07 EP EP05076762A patent/EP1600773B1/en not_active Expired - Lifetime
- 2001-03-07 WO PCT/GB2001/000990 patent/WO2001067099A1/en active IP Right Grant
- 2001-03-07 EP EP10177789.4A patent/EP2261657B1/en not_active Expired - Lifetime
- 2001-03-07 AU AU2001237587A patent/AU2001237587B2/en not_active Ceased
- 2001-03-07 CZ CZ20023332A patent/CZ20023332A3/en unknown
- 2001-03-07 AU AU3758701A patent/AU3758701A/en active Pending
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- 2001-03-07 DE DE60137802T patent/DE60137802D1/en not_active Expired - Lifetime
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- 2001-03-07 CN CNB018086462A patent/CN1193230C/en not_active Expired - Lifetime
- 2001-03-07 AT AT05076762T patent/ATE423969T1/en active
- 2001-03-07 DK DK01910003T patent/DK1261868T3/en active
- 2001-03-07 DK DK05076762T patent/DK1600773T3/en active
- 2001-03-07 CA CA2402139A patent/CA2402139C/en not_active Expired - Lifetime
- 2001-03-07 KR KR1020077020140A patent/KR100872009B1/en active IP Right Grant
- 2001-03-07 PL PL01364990A patent/PL364990A1/en not_active Application Discontinuation
- 2001-03-07 AT AT09002602T patent/ATE542132T1/en active
- 2001-03-07 ES ES01910003T patent/ES2249413T3/en not_active Expired - Lifetime
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- 2001-03-07 JP JP2001566021A patent/JP4832695B2/en not_active Expired - Lifetime
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2002
- 2002-09-05 IL IL151643A patent/IL151643A/en not_active IP Right Cessation
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2003
- 2003-03-10 HK HK03101720A patent/HK1049696A1/en not_active IP Right Cessation
- 2003-05-07 US US10/431,140 patent/US7250105B1/en not_active Expired - Lifetime
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2005
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2006
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